<template>
      <section class="home">
        <!--首页头部-->
        <HeaderTop :title="address.name">
          <router-link class="header_search" slot="left" to="/search">
            <i class="iconfont icon-sousuo"></i>
          </router-link>
          <!-- user.id有值表明登录，跳转用户信息页，否则到登录页-->
          <router-link class="header_login" slot="right" :to="userInfo._id ? '/userInfo' : '/login' ">
            <span class="header_login_text" v-if="!userInfo._id">登录|注册</span>
            <span class="header_login_text" v-else>
              <i class="iconfont icon-geren"></i>
            </span>
          </router-link>
        </HeaderTop>
        <!--首页导航-->
        <nav class="home_nav">
          <div class="swiper-container" v-if="foodType.length">
            <div class="swiper-wrapper">
              <div class="swiper-slide" v-for="(foodType, index) in foodTypeArr" :key="index">
                <a href="javascript:" class="link_to_food"  v-for="(food,index) in foodType" :key="index">
                  <div class="food_container" @click="foodTypeFun(food)" :food="food">
                    <img :src="base_imageurl+food.image_url">
                  </div>
                  <span>{{food.title}}</span>
                </a>
              </div>
            </div>
            <div class="swiper-pagination"></div>
            </div>
          <img src="./images/msite_back.svg" alt="back" v-else>
        </nav>
        <!--首页附近商家-->
        <div class="home_shop_list">
          <div class="shop_header">
            <i class="iconfont icon-xuanxiang"></i>
            <span class="shop_header_title">附近商家</span>
            <ShopList/>
          </div>
        </div>
      </section>
</template>

<script>
import HeaderTop from '../../components/HeaderTop/HeaderTop.vue'
import ShopList from '../../components/ShopList/ShopList.vue'
import Swiper from 'swiper'
import 'swiper/dist/css/swiper.min.css'
import {mapState} from 'vuex'

export default {
  data () {
    return {
      // 异步获取食品类型的图片路径的前缀地址
      base_imageurl: 'https://fuss10.elemecdn.com'
    }
  },
  components: {
    HeaderTop,
    ShopList
  },
  computed: {
    ...mapState(['address', 'foodType', 'userInfo']),
    /*
      根据categorys一维数组生成一个二维数组
      小数组中元素数量最大为8
      */
    foodTypeArr () {
      const {foodType} = this
      // 准备空的二维数组
      const arr = []
      let minArr = []
      // 遍历foodType
      foodType.forEach(c => {
        if (minArr.length === 8) {
          arr.push(minArr)
          minArr = []
        }
        minArr.push(c)
      })
      if (minArr) {
        arr.push(minArr)
      }
      return arr
    }
  },
  watch: {
    foodType (value) { // categorys数组中有数据了，在异步更新界面之前执行
      // 希望界面更新就立即创建swiper对象
      this.$nextTick(() => { // 一旦界面更新立即调用(要写在数据更新之后)
        // 创建一个swiper实例对象实现轮播
        // eslint-disable-next-line no-new
        new Swiper('.swiper-container', {
          loop: true, // 循环轮播
          // 如果需要分页器
          pagination: {
            el: '.swiper-pagination'
          }
        })
      })
    }
  },
  mounted () {
    this.$store.dispatch('reqFoodType')
  },
  methods: {
    foodTypeFun (food) {
      /**
       *  通过路由传值（无视组件间关系）
       *      1.添加值入路由路径
       * */
      this.$router.push({
        path: '/shopType',
        query: {params: JSON.stringify(food)}
      })
    }
  }
}
</script>

<style lang="stylus" rel="stylesheet/stylus">
@import '../../common/stylus/mixins.styl'
  .home
    width 100%
    .home_nav
      bottom-border-1px(#e4e4e4)
      margin-top 45px
      height 200px
      background #fff
      .swiper-container
        width 100%
        height 100%
        .swiper-wrapper
          width 100%
          height 100%
          .swiper-slide
            display flex
            justify-content center
            align-items flex-start
            flex-wrap wrap
            .link_to_food
              width 25%
              .food_container
                display block
                width 100%
                text-align center
                padding-bottom 10px
                font-size 0
                img
                  display inline-block
                  width 50px
                  height 50px
              span
                display block
                width 100%
                text-align center
                font-size 13px
                color #666
          .swiper-pagination
            >span.swiper-pagination-bullet-active
              background #02a774
    .home_shop_list
          top-border-1px(#e4e4e4)
          margin-top 10px
          background #fff
          .shop_header
            padding 10px 10px 0
          .shop_icon
            margin-left 5px
            color #999
          .shop_header_title
            color #999
            font-size 14px
            line-height 20px

</style>
